Electron-Doping Effect on the Magnetic-Field-Sensitive Dielectric Anomaly in CaMn1– x Sb x O3

We measured the temperature dependence of the dielectric constant of the electron-doped manganite CaMn 1-x Sb x O 3 (x = 0.1, 0.12, 0.13, 0.15, and 0.2). The real part exhibits a broad peak and the imaginary part exhibits a shoulder structure at a lower temperature in all the samples, suggesting a gradual growth of clusters which has a dipole ordering. We newly revealed that the temperatures of these dielectric anomalies are enhanced by more than 90 K by the Sb substitution from x = 0.1 to x = 0.2. The result indicates that the carrier concentration should be a decisive parameter for the dipole ordering in CaMn 1-x Sb x O 3 . Moreover, a magnetocapacitive effect is observed in all the samples.